Silane modified alkylene-alkyl acrylate copolymers are particularly desirable for use in commercial applications as these polymers and compositions based thereon can be cured by a simple water treatment, as opposed to the more conventional peroxide curing, to crosslinked products of high crosslinked density. As a result, silane modified alkylene-alkyl acrylate copolymers and compositions based on these polymers are especially useful in extrusion applications, being capable of extrusion under a wide latitude of processing conditions, as for example, temperatures far in excess of maximum processing temperatures used in extruding peroxide containing compositions.
The production of silane modified alkylene-alkyl acrylate copolymers is carried out, conveniently, by admixing a polysiloxane with an alkylene-alkyl acrylate copolymer, in the presence of an organo titanate, as described in detail in my copending application Ser. No. 192,319 filed Sept. 30, 1980 now U.S. Pat. No. 4,328,323 granted May 4, 1982, the disclosure of which is incorporated herein by reference, with the result that the polysiloxane reacts with the alkylene-alkyl acrylate copolymer yielding a water-curable, silane modified alkylene-alkyl acrylate copolymer.
In carrying out this reaction, care must be taken to protect the polysiloxane from moisture. Polysiloxanes hydrolyze rapidly, on contact with moisture, and condense to gelled products which, for all practical purposes, are useless. In addition to the problem of moisture sensitivity, it is difficult, in some instances, to blend the polysiloxane-alkylene-alkyl acrylate reaction mixtures, particularly when the reaction mixtures are highly filled with additives. Consequently, additional time and/or processing steps may be required in order to homogenize the reaction mixtures, which is necessary in order to effect substantially complete reaction between the polysiloxane and the alkylene-alkyl acrylate copolymer.